The present invention relates to a data display apparatus that displays a plurality of types of measurement data measured in a time serial manner by a signal measurement section on a predetermined coordinate system.
Recently, simulation devices are used in various fields for the purpose of reducing time or cost needed for developing products or the like and preliminarily verifying safety of the products; or for the purpose of conducting simulation-based training for operating an actual plant. According to the simulation devices, a computer calculates models that formulate the functions of mechanisms or electrical signals in actual products or plants, and the characteristics of the product or the like are identified based on the calculation results, thereby preliminarily resolving possible problems or getting trained for the problems.
As an example of such simulation devices, Patent Document 1 discloses a simulation device for monitoring the operation of an engine control unit of a vehicle and evaluating the performance by creating an imaginary environment in which an engine control unit for a vehicle is mounted on an actual vehicle. The simulation device includes a model computer unit that is operated as a vehicle model corresponding to an imaginary vehicle in accordance with preset program and that generates simulation signals corresponding to each engine excursion and each crank angle and gives the simulation signals to the engine control unit of the vehicle, thereby monitoring the operation and evaluating the performance. The simulation device also includes a signal generation unit that is operated in cooperation with the model computer unit and that generates signals necessary for the vehicle model of the model computer unit.
The simulation device is also provided with a signal measurement section that measures time-serial control signals such as fuel injection pulses or ignition pulses output from the engine control unit in response to simulated crank pulse signals output to the engine control unit from a simulation calculation section that simulates an engine and a data display apparatus that displays a plurality of types of measurement data measured by the signal measurement section on a predetermined coordinate system. With this arrangement, an operator can have a view of the measurement data displayed on a monitor and determine whether the engine control unit is operating properly.    Patent Document 1: Japanese Patent Publication No. 11-326135A
However, according to the data display apparatus disclosed in Patent Document 1, a plotting processing section plots the measurement data measured in a time serial manner by the signal measurement section on a two-dimensional coordinate system wherein X and Y axes are fixed to time and signal values and output the plot results to an output unit such as a monitor. Therefore, it is difficult to evaluate the correlation between plural related signals.
In order to solve the problem and enable evaluation of correlation between specific measurement data, separate plotting processing programs may be constructed, which, however, require specific-purpose program developments. Thus, it is difficult to flexibly evaluate the correlation between arbitrary measurement data.
Therefore, when evaluating the correlation between present measurement data and ideal model data or measurement data that were sampled in the past, it is necessary to print the measurement data on a recording sheet for precise investigation, which may complicate the evaluation work.